package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import lombok.var;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.domain.Range;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT ;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
//    private final BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
    private static final ExecutorService SECKILL_ORDER_EXECUTOR=Executors.newSingleThreadExecutor();
    @PostConstruct
    public void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    String queueName="stream.orders";
    private class VoucherOrderHandler implements Runnable {
        @Override
        public void run() {
            while (true) {
                try {
                    //1.获取消息队列中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed()));
                    //2.判断消息是否成功
                    if(list==null||list.isEmpty()){
                        //2.1若不成功，下一循环
                        continue;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //3.若有，开始下单
                    handleVoucherOrder(voucherOrder);
                    //4.ack确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }
            }
        }
    }

    private void handlePendingList() {
        while (true) {
                //1.获取pending-list中的未处理消息
                PendingMessages pendingMessages = stringRedisTemplate.opsForStream().pending(
                        queueName,
                        Consumer.from("g1", "c1")
                );
                if (pendingMessages.isEmpty()) {
                    break;
                }
                pendingMessages.forEach(pendingMessage -> {
                    List<MapRecord<String, Object, Object>> records = stringRedisTemplate.opsForStream().range(
                                    queueName, Range.closed(pendingMessage.getIdAsString(), pendingMessage.getIdAsString())
                            );
                    MapRecord<String, Object, Object> record = records.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //3.若有，开始下单
                    handleVoucherOrder(voucherOrder);
                    //4.ack确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                }
                );
        }
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        var lock = redissonClient.getLock("lock:order:" + userId);
        boolean islock = lock.tryLock();
        if (!islock) {
            log.error("不允许重复下单");
            return;
        }
        try {
            proxy.getResult(voucherOrder);
        } catch (IllegalStateException e) {
            throw new RuntimeException(e);
        } finally {
            lock.unlock();
        }

    }
    private  IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        long orderId = redisIdWorker.nextId("order");
        var userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString(),
                String.valueOf(orderId));
        //2.判断结果是否为0
        //2.2 为非0，代表没有购买资格
        if (result.intValue() != 0) {
            return Result.fail(result == 1 ? "库存不足" : "不能重复下单");
        }
        return Result.ok(orderId);
    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        var userId = UserHolder.getUser().getId();
//        //1.执行lua脚本
//        Long result = stringRedisTemplate.execute(
//                SECKILL_SCRIPT,
//                Collections.emptyList(),
//                voucherId.toString(),
//                userId.toString());
//        //2.判断结果是否为0
//        //2.2 为非0，代表没有购买资格
//        if (result.intValue() != 0) {
//            return Result.fail(result == 1 ? "库存不足" : "不能重复下单");
//        }
//        //2.1 为0，下单成功
//        long orderId = redisIdWorker.nextId("order");
//        VoucherOrder voucherOrder = new VoucherOrder();
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//        orderTasks.add(voucherOrder);
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        return Result.ok(orderId);
//    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        var voucher = seckillVoucherService.getById(voucherId);
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            return Result.fail("秒杀尚未开始");
//        }
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已经结束");
//        }
//        if (voucher.getStock() < 1) {
//            return Result.fail("库存不足");
//        }
//        Long userId = UserHolder.getUser().getId();
//        var lock = redissonClient.getLock("lock:order:" + userId);
//        boolean islock = lock.tryLock();
//        if (!islock) {
//            return Result.fail("请勿重复下单");
//        }
////        synchronized (userId.toString().intern()){
////            IVoucherOrderService proxy =(IVoucherOrderService) AopContext.currentProxy();
////            return proxy.getResult(voucherId);
////        }
//        try {
//            IVoucherOrderService proxy =(IVoucherOrderService) AopContext.currentProxy();
//            return proxy.getResult(voucherId);
//        } catch (IllegalStateException e) {
//            throw new RuntimeException(e);
//        } finally {
//            lock.unlock();
//        }
//    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void getResult(VoucherOrder voucherOrder) {

        Long userId = voucherOrder.getUserId();
        Long voucherId = voucherOrder.getVoucherId();
        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        if (count > 0) {
            log.error("用户已经购买过一次");
            return;
        }
        var success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherId)
                .gt("stock",0)
                .update();
        if (!success) {
            log.error("库存不足");
            return ;
        }
        save(voucherOrder);
    }
}
